Great Southern Copper PLC (LSE:GSCU) has reported a busy first half marked by high-grade drilling results, expanded mineralised trends and early signs of a significant gold system emerging across its Especularita project in Chile.
The company’s interim results show further progress at Cerro Negro, where Phase I drilling at the historic Mostaza mine confirmed the high-grade nature of the system.
Assays included copper grades as high as 16.15% and silver at 646 grammes per tonne, with standout intervals such as 33 metres at 1.96% copper and 60.6 g/t silver. Follow-up work extended the mineralised strike by a further 2km to the south, defining what the company calls the Mostaza Fault Zone.
Geophysical surveys strengthened confidence in deeper structural targets along this trend, identifying an anomaly consistent with the sulphide mineralisation already drilled beneath the mine.
Phase II drilling continued the momentum, delivering further thick and high-grade intercepts, including 13.9m at 1.74% copper and 153 g/t silver, and 5m at 3.04% copper and 322.4 g/t silver, while also confirming a new mineralised lens north of the main system.
Phase III drilling began late in the period, with additional rigs mobilised shortly afterwards to accelerate work. The expanded programme is designed to test extensions of known mineralisation, probe beneath shallow leached zones where silver grades strengthened, and step out along the broader Mostaza Fault.
Post-period sampling at the Monolith prospect added another layer of interest, identifying a 50-metre-wide zone of copper-silver mineralisation with grades up to 271 g/t silver and 2.05% copper. A third drill rig has since been deployed to begin reverse-circulation drilling across new oxide targets.
At Viuda Negra, early drilling confirmed a porphyry-style gold system. Scout campaigns intersected broad alteration zones and long mineralised intervals, including 121.5 metres at 0.11 g/t gold and 0.05% copper, outlining a system roughly 1.2km by 0.8km and still open.
Financially, Great Southern Copper strengthened its position with a £2.5 million private placing in November to support ongoing exploration. It posted a modest £1 million operating loss for the period.
Chief executive Sam Garrett said the period showed “excellent progress”, adding that the company is well-positioned as multi-rig exploration continues across its key targets.